Poly tertiary amide and colloidal silica for LEP adhesion
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Solution Overview
Problem
Liquid electrophotographic (LEP) printed images face challenges in adhesion to substrates, particularly due to inconsistencies across different paper grades and the difficulty in achieving near-perfect adhesion as per HP standard procedures, with existing solutions like polyethylene/acrylic acid being inefficient and causing surface friction issues.
Innovation Solution
A water-based composition comprising an adhesion-promoting polymer with a tertiary amide group and colloidal silica, optionally with a polymeric binder, is applied to the substrate to enhance the adhesion of LEP printed images, providing improved adhesion without lowering the pH or interfering with optical brightening agents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If polyethylene/acrylic acid is used to improve adhesion of LEP printed images, then adhesion is improved, but surface friction is reduced and deposits are formed during coating
Solution Approach 1:
The patent changes the chemical composition parameters by using poly tertiary amide (such as polyethyloxazoline or polyvinyl pyrrolidone) instead of polyethylene/acrylic acid, and optimizes the concentration ratio between the polymer and colloidal silica to achieve improved adhesion without the harmful side effects of friction reduction and deposit formation
Solution Approach 2:
The patent replaces the problematic polyethylene/acrylic acid with a more efficient and cleaner alternative composition consisting of poly tertiary amide and colloidal silica, which achieves the same adhesion improvement without creating deposits or reducing surface friction
2Strength
If poly tertiary amide is used to improve adhesion, then adhesion is improved, but efficiency is reduced on substrates with open or porous structure
Solution Approach 1:
The patent creates a composite treatment composition by combining poly tertiary amide (adhesion promoter) with colloidal silica, where the colloidal silica acts as a binder that fills the porous structure of the substrate and provides mechanical anchoring, while the poly tertiary amide provides chemical adhesion promotion at the surface, achieving synergistic effect on both porous and non-porous substrates
Solution Approach 2:
The colloidal silica serves as an intermediary material that bridges the gap between the substrate surface and the liquid toner, particularly on porous substrates where it fills voids and creates a uniform surface that enhances the effectiveness of the poly tertiary amide adhesion promoter
3Reliability
If aluminum salts are added to overcome loss of efficiency on porous substrates, then adhesion on porous substrates is improved, but pH is significantly lowered and deposition issues occur
Solution Approach 1:
The patent replaces aluminum salts with a combination of poly tertiary amide and colloidal silica, which achieves the same goal of improving adhesion on porous substrates without the harmful side effects of pH reduction and deposition problems, providing a cleaner and more reliable solution
4Strength
If conventional compositions are applied to improve adhesion, then adhesion is improved, but inconsistencies remain depending on paper grade
Solution Approach 1:
The patent develops a universal treatment composition containing poly tertiary amide and colloidal silica that effectively improves adhesion across all paper grades, from porous to non-porous substrates, eliminating the need for grade-specific formulations and achieving consistent adhesion performance universally
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The composition significantly improves the adhesion of LEP printed images to substrates, achieving adhesion retention of over 80% as tested by the Tape Pull Test, with the colloidal silica enhancing the efficacy of the adhesion-promoting polymer and ensuring consistent performance across various substrate types.
Implementation Method 1
A water-based composition is provided for treating a substrate... an adhesion promoting polymer comprising a polymer containing one or more repeating units, wherein the one or more repeating units includes a tertiary amide group
Implementation Method 2
a colloidal silica... The colloidal silica enhances the efficacy of the adhesion-promoting polymer and ensures consistent performance across various substrate types
Data Source
AI summary
Compositions and methods that generally relates to treating a substrate and for improving adhesion of an image to a treated substrate and more particularly relates to systems and methods utilizing a combination of a poly tertiary amide, colloidal silica, and optionally a polymeric binder, for treating a substrate and for improving adhesion of an electrographic image to a treated substrate.